This one simple trick increased the joy in my life: To first observe, then judge. Two steps. Separated in time, separated as cognitive steps.
Whenever I feel myself floating high on assumptions, fuelled (usually) by anger and righteousness - I let go. And I feel myself dive back into the deep pool of facts. To swim through that again.
Gathering first what else is true. I get out, and then try to judge what I am going to do with that.
Always it changes my perspective and calms me down.
Often, I need to dip back into that pool again. Most often, I catch myself, too late, floating on anger fuelled clouds divorced from reality.
Then I let go, again.